The unique chemistry and internal molecular association of asphalt are responsible for its mechanical properties and hence for its use as a binder in asphalt concrete pavement. Large tonnages of asphalt are used every year in constructing roads throughout the world; thus any improvement in its properties, no matter how small, translates into considerable cost savings. The present invention is a means and method of improving the rheological properties of crumb rubber modified asphalt which is later used in pavement.
Adding crumb rubber to hot asphalt results in improved properties such as a wider useful temperature range. However, reports of performance of prior art crumb rubber modified asphalt concrete vary considerably; some pavements ravel after use, sometimes there is a decrease in the mechanical properties of the binder, and sometimes there are inconsistencies in the applicability of the asphalt concrete in the field. These variations result from differences in the types of asphalt; the source, composition, size, and process of making the crumb rubber particles; and in the process of incorporating the crumb rubber particles in the asphalt.
Accordingly, it is an object of the present invention to provide a means and method of improving the rheological properties of crumb rubber modified asphalt.
It is a further object of the present invention to provide such means and method which can be utilized with a broad range of asphalts.
It is a further object of the present invention to provide such means and method which are easy and economical to implement.
It is a further object of the present invention to provide such means and method which are not harmful to the environment.
It is a further object of the present invention to provide a means and method for improving the solubility and dispersion of crumb rubber in asphalt.